1. Field of the Invention
The present invention relates to a method for reforming a base surface before thin film deposition, a method for manufacturing the semiconductor device and an equipment for manufacturing the same, and more particularly to the method for reforming the base surface before the thin film deposition, the method for manufacturing the semiconductor device and the equipment for manufacturing the same in the thin film deposition by CVD (Chemical Vapor deposition) method using O3/TEOS (Tetraehylorthosilicate) system reaction gas (the gases containing O3 and TEOS).
2. Description of the Prior Art
It is known that a property of the film formed on the base layer is greatly influenced by the surface condition of the base layer.
Especially, characteristics of CVD film deposited by the CVD method using an O3/TEOS gas system for thin film deposition greatly depends upon the surface condition of the base layer. For example, the growth rate of the thin film is reduced remarkably and the deposited film becomes porous when the surface of the base layer is hydrophilic.
Therefore, the fluidity, the flatness, the embedding ability and the step-coverage of the film deposited on a surface of a base layer are lowered.
It is thought that such deposition irregularity is caused by an intermediate generated in the reaction of O3 gas and TEOS gas which is a polymer with hydrophilicity, and it is shown that a film can not be deposited on the surface of the base layer when the surface of the base layer is hydrophilic.
Methods eliminating dependence on the surface of the base layer described above, include
(1) a method of plasma processing using the gases such as NH3, H2 or the like,
(2) a method using an insulating film formed using a low concentration of O3 as the base layer,
(3) a method using an insulating film formed by a plasma CVD method as the base layer,
(4) a method processing the surface of the base layer, before the thin film deposition, with alcohol, or the like.
However, there are problems as described below in the above-mentioned methods. That is, (1) In the method of plasma processing, using gases such as NH3, H2 or the like, films having good embedding ability and step-coverage have not been formed, when depositing the film on very narrow regions such as via holes and contact holes. (2) In the method using the insulating film formed by a plasma CVD method as the base layer, it has been difficult to form the insulating film being used as the base layer on the very narrow regions such as the via holes and the contact holes. (3) Also in the method using the insulating film formed by the plasma CVD method as the base layer, it has been difficult to form the insulating film being used as the base layer on the very narrow regions such as the via holes and the contact holes. (4) In the method processing the surface of the base layer before the thin film deposition with alcohol, the effect of reform is poor in reproduction and, in addition, the effect of reform processing of the base surface can not be maintained.
The object of the invention is to provide a method for reforming a base surface before the thin film deposition, a method for manufacturing a semiconductor device and apparatus for manufacturing the same, capable of maintaining a reformed base layer surface, to improve the fluidity, the flatness, the embedding ability and the step-coverage of the film deposited on the surface of the base layer and, especially, to improve the embedding ability and the step-coverage of the film formed in the very narrow regions such as the via-holes and the contact holes of the base layer.
In the invention, reform of the surface of the base layer in a reaction chamber is performed with a gas containing a halogen, and subsequently, a thin film can be deposited on the reformed surface of the base layer.
According to experiments of the inventor of this application, it has been found that when reform of the surface of the base layer is performed by a gas containing a halogen element, the effect of reform of the base layer surface can be maintained for the long term as compared to the prior art, in addition, the fluidity, the flatness, the embedding ability and the step-coverage of the film formed on the reformed surface of the base layer can be improved.
Especially, the embedding ability and the step-coverage of the film formed in the via holes or the like can be improved, even though there are the very narrow-concave regions such as the via holes and the contact holes in the base layer.
Moreover, the fluidity, the flatness, the embedding ability and the step-coverage of the film formed on the surface of the base layer thereof can be improved, when reform of the surface of the base layer is performed while heating the base layer.
Especially, it was confirmed that the reformed effect can be further enhanced by heating the surface to a temperature of 100xc2x0 C. or more while reforming the surface.